There are three airports that serve the greater Baltimore-Washington area.
Amtrak services Baltimore with stops at Baltimore Penn Station located at 1500 North Charles Street and Baltimore/BWI-Thurgood Marshall Station at 7 Amtrak Way, Amtrak/MARC Station.
The Acela Express and Northeast Regional lines arrive at Baltimore Penn Station 18 times throughout the day.
Baltimore is accessible by various interstates.
Each of the airports is served by various ground transportation carriers. Washington Flyer serves DCA and IAD while SuperShuttle serves BWI. Visit their websites for more information on cost and schedules.
Downtown Baltimore can be reached via Amtrak trains (Penn Station is the primary stop) and Light Rail from the BWI airport. The Light Rail is $1.60 each way.